Field of the Invention
The present invention relates to a liquid ejecting apparatus, in which a liquid ejecting unit ejects liquid, and furthermore, mist generated between a print medium and the liquid ejecting unit can be removed.
Description of the Related Art
In a liquid ejecting apparatus in which liquid is ejected onto a print medium so as to perform printing, fine liquid droplets called mist floating between a print head and the print medium without landing on the print medium are generated during liquid ejection as well as main droplets as liquid droplets contributive to image formation on the print medium. The mist adheres to various portions inside of the main body of the liquid ejecting apparatus such as the print medium and the print head on an airflow produced inside of the main body of the liquid ejecting apparatus. In a case where mist adheres to, in particular, a surface (i.e., an ejection port surface), at which an ejection port for ejecting ink therethrough is formed, of the print head in a large quantity, the mist coalesces to become a large liquid droplet, which closes the ejection port, possibly resulting in deficient ejection of the ejection port. In this case, the ejection performance of the print head is markedly reduced. This is a factor of degradation of a print image. Moreover, in a case where the mist adheres to a portion which is brought into direct contact with the print medium such as a pinch roller, the ink adheres to the print medium, thereby degrading an image.
In order to solve the above-described problem caused by mist, mist floating between a print head and a print medium has been sucked through a suction hole. However, in a case where the liquid ejecting apparatus is configured such that air is sucked by using only the suction hole, an airflow is produced toward the suction hole, and therefore, the landing position of a main droplet ejected from an ejection port is misregistered by the influence of the airflow.
In view of the above, Japanese Patent Laid-open No. 2010-137483 and U.S. Patent Laid-open No. 2006238561 disclose blowing and sucking air between a print head and a print medium in a liquid ejecting apparatus so as to remove mist on an airflow.
However, in an apparatus disclosed in Japanese Patent Laid-open No. 2010-137483, in a case where an airflow is produced in a large quantity by sucking and blowing air, the landing position of a liquid droplet ejected from the print head is misregistered from a proper landing position by the influence of the airflow, possibly resulting in degrading an image. To the contrary, in a case where air is sucked and blown in a small quantity, the mist cannot be sufficiently removed, whereby the mist possibly causes a smudge.
Moreover, in an apparatus disclosed in U.S. Patent Laid-open No. 2006238561, mist is removed by using both a suction hole and a blowing hole that are formed between adjacent print heads, thereby suppressing the production of an airflow that may degrade an image. However, even the technique disclosed in U.S. Patent Laid-open No. 2006238561 cannot remove mist in a case where air is sucked or blown within a predetermined range of quantities, thus preventing satisfactory elimination of a smudge on component parts caused by the adhesion of the mist.
As described above, the conventional liquid ejecting apparatuses, in which the mist can be removed while both of sucking and blowing operations are optimized, require trial and error using an actual device or in simulation. A definite measure or the like has not been found yet.